<template>
  <view class="uni-combox" :class="border ? '' : 'uni-combox__no-border'">
    <view v-if="label" class="uni-combox__label" :style="labelStyle">
      <text>{{ label }}</text>
    </view>
    <view class="uni-combox__input-box">
      <input
        class="uni-combox__input"
        type="text"
        :placeholder="placeholder"
        placeholder-class="uni-combox__input-plac"
        v-model="inputLabel"
        @input="onInput"
        @focus="onFocus"
        @blur="onBlur"
      />
      <uni-icons
        :type="showSelector ? 'top' : 'bottom'"
        size="14"
        color="#999"
        @click="toggleSelector"
      >
      </uni-icons>
    </view>
    <view class="uni-combox__selector" v-if="showSelector">
      <view class="uni-popper__arrow"></view>
      <scroll-view scroll-y="true" class="uni-combox__selector-scroll">
        <view class="uni-combox__selector-empty" v-if="filterCandidatesLength === 0">
          <text>{{ emptyTips }}</text>
        </view>
        <view
          class="uni-combox__selector-item"
          v-for="(item, index) in candidates"
          :key="index"
          @click="onSelectorClick(index)"
        >
          <text>{{ item[keyLabel] }}</text>
        </view>
      </scroll-view>
    </view>
  </view>
</template>

<script>
  /**
   * Combox 组合输入框
   * @description 组合输入框一般用于既可以输入也可以选择的场景
   * @tutorial https://ext.dcloud.net.cn/plugin?id=1261
   * @property {String} label 左侧文字
   * @property {String} labelWidth 左侧内容宽度
   * @property {String} placeholder 输入框占位符
   * @property {Array<Object>} candidates 候选项列表
   * @property {String} emptyTips 筛选结果为空时显示的文字
   * @property {String} value 组合框的值
   * @property {String} keyValue 选择的值字段名
   * @property {String} keyLabel 选择的标签字段名
   */
  export default {
    name: 'SearchSelect',
    emits: ['input', 'update:modelValue'],
    props: {
      border: {
        type: Boolean,
        default: true,
      },
      label: {
        type: String,
        default: '',
      },
      labelWidth: {
        type: String,
        default: 'auto',
      },
      placeholder: {
        type: String,
        default: '',
      },
      candidates: {
        type: Array,
        default: () => {
          return [];
        },
      },
      keyValue: {
        type: String,
        default: 'id',
      },
      keyLabel: {
        type: String,
        default: 'label',
      },
      emptyTips: {
        type: String,
        default: '无匹配项',
      },
      afterSelect: {
        type: Function,
        default: () => {},
      },
      // #ifndef VUE3
      value: {
        type: [String, Number],
        default: '',
      },
      // #endif
      // #ifdef VUE3
      modelValue: {
        type: [String, Number],
        default: '',
      },
      // #endif
    },
    data() {
      return {
        showSelector: false,
        inputLabel: '',
        inputVal: '',
      };
    },
    computed: {
      labelStyle() {
        if (this.labelWidth === 'auto') {
          return '';
        }
        return `width: ${this.labelWidth}`;
      },

      filterCandidatesLength() {
        return this.candidates.length;
      },
    },
    watch: {
      // #ifndef VUE3
      value: {
        handler(newVal) {
          this.inputVal = newVal;
        },
        immediate: true,
      },
      // #endif
      // #ifdef VUE3
      modelValue: {
        handler(newVal) {
          this.inputVal = newVal;
        },
        immediate: true,
      },
      // #endif
    },
    methods: {
      toggleSelector() {
        this.showSelector = !this.showSelector;
      },
      onFocus() {
        this.showSelector = true;
      },
      onBlur() {
        setTimeout(() => {
          this.showSelector = false;
        }, 153);
      },
      onSelectorClick(index) {
        this.inputLabel = this.candidates[index][this.keyLabel];
        this.inputVal = this.candidates[index][this.keyValue];
        this.showSelector = false;
        this.$emit('update:modelValue', this.inputLabel);
        this.$emit('afterSelect', { index, label: this.inputLabel, value: this.inputVal });
      },
      onInput() {
        setTimeout(() => {
          this.$emit('input', this.inputLabel);
          this.$emit('update:modelValue', this.inputLabel);
        });
      },
    },
  };
</script>

<style lang="scss">
  .uni-combox {
    font-size: 14px;
    border: 1px solid #dcdfe6;
    border-radius: 4px;
    padding: 6px 10px;
    position: relative;
    /* #ifndef APP-NVUE */
    display: flex;
    /* #endif */
    // height: 40px;
    flex-direction: row;
    align-items: center;
    // border-bottom: solid 1px #DDDDDD;
  }

  .uni-combox__label {
    font-size: 16px;
    line-height: 22px;
    padding-right: 10px;
    color: #999999;
  }

  .uni-combox__input-box {
    position: relative;
    /* #ifndef APP-NVUE */
    display: flex;
    /* #endif */
    flex: 1;
    flex-direction: row;
    align-items: center;
  }

  .uni-combox__input {
    flex: 1;
    font-size: 14px;
    height: 22px;
    line-height: 22px;
  }

  .uni-combox__input-plac {
    font-size: 14px;
    color: #999;
  }

  .uni-combox__selector {
    /* #ifndef APP-NVUE */
    box-sizing: border-box;
    /* #endif */
    position: absolute;
    top: calc(100% + 12px);
    left: 0;
    width: 100%;
    background-color: #ffffff;
    border: 1px solid #ebeef5;
    border-radius: 6px;
    box-shadow: 0 2px 12px 0 rgba(0, 0, 0, 0.1);
    z-index: 2;
    padding: 4px 0;
  }

  .uni-combox__selector-scroll {
    /* #ifndef APP-NVUE */
    max-height: 200px;
    box-sizing: border-box;
    /* #endif */
  }

  .uni-combox__selector-empty,
  .uni-combox__selector-item {
    /* #ifndef APP-NVUE */
    display: flex;
    cursor: pointer;
    /* #endif */
    line-height: 36px;
    font-size: 14px;
    text-align: center;
    // border-bottom: solid 1px #DDDDDD;
    padding: 0px 10px;
  }

  .uni-combox__selector-item:hover {
    background-color: #f9f9f9;
  }

  .uni-combox__selector-empty:last-child,
  .uni-combox__selector-item:last-child {
    /* #ifndef APP-NVUE */
    border-bottom: none;
    /* #endif */
  }

  // picker 弹出层通用的指示小三角
  .uni-popper__arrow,
  .uni-popper__arrow::after {
    position: absolute;
    display: block;
    width: 0;
    height: 0;
    border-color: transparent;
    border-style: solid;
    border-width: 6px;
  }

  .uni-popper__arrow {
    filter: drop-shadow(0 2px 12px rgba(0, 0, 0, 0.03));
    top: -6px;
    left: 10%;
    margin-right: 3px;
    border-top-width: 0;
    border-bottom-color: #ebeef5;
  }

  .uni-popper__arrow::after {
    content: ' ';
    top: 1px;
    margin-left: -6px;
    border-top-width: 0;
    border-bottom-color: #fff;
  }

  .uni-combox__no-border {
    border: none;
  }
</style>
